Straw-braid sewing machine



Filed June 24, 1956 4 Shets-Sheet 1 Rudolph Becker June 8, 1937. R. BECKER 2,082,784

STRAW BRAID SEWING MACHINE Filed June 24, 1936 4 Sheets-Sheet 2 wirweik PJZNCW 2154,

June 8, 1937. R. BECKER STRAW BRAID SEWING MACHINE.

Filed June 24, 1936 4 Sheets-Sheet 3 W w r m u w m M h, a m z 1 y m a M 6 Jf w June 8, 1937.

Wifwe 46 1 WWW R. BECKER STRAW BRAID SEWING MACHINE Filed June 24, 1956 4 Sheets-Sheet 4 grwcwbom Rudolph Becker- Patented June 1937 STRAW-BRAID SEWING MACHINE Rudolph Becker, North Plainficld, N. J., assignor to The Singer Manufacturing Company, Elizaboth, N. J., a corporation of New Jersey Application June 24, 1936, sci-m No. 86,903

'1 Claims. (01. 112-23) i 10 supporting slide-frame against a heavy springpressure such as heretofore used to resist dis-'- placement of the slide-frame and parts of the needle-stroke-varying mechanism connected with it, under operative stresses set up in the running 15 of the machine.

With the above and other objects in view, as will hereinafter appear, the invention comprises the devices, combinations, and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

25 Referring to the accompanying drawings, Fig. 1 is a front side elevation, partly in section, of a sewing machine embodying the invention. Fig. 2 is a fragmentary front end elevation of the machine. Fig. 3 is a similar view with the press- 30 er-foot and iooper-supporting slide-frame raised for the removal and insertion of work. Fig. 4 is a horizontal section through the machine bed showing parts of the needle-bar-actuating mechanism in plan. Fig. 5 is a vertical transverse 35 section through the bracket-arm of the machine adjacent the looper-supportlng slide-frame and presser-bar. Fig. 6 is a perspective view of the presser-foot and bar. Fig. 7 is a section approximately on the line 'l-i, Fig. 1. Fig. 8 is a frag- 40 mentary view similar to Fig. '1, showing the relative movement between two yieldingly connected parts of, the looper-supporting slide-frame positioning means, when the presser-foot is lifted to the position shown in Fig. 3. Fig. 9 is a sec- 45 tion on the line 9- 3, Fig. I. Fig. 10 is a section on the line iiil0, Fig. '7. Fig, 11 is a rear elevation of the anchorage for the presser-bar spring, and Fig. 12 is a section on the line i2l2, Fig. 4. The machine, except as hereinafter described,

50 is constructed substantially in accordance with the disclosure of said U. S. Patent No. 2,034,706.

It has a frame including the bed i and standard 2 of the overhanging bracket-arm 3 terminating in the head 4. Journaled in the bed i is the 55 main shaft 5 having the'needle-bar driving ballcrank 6 which is connected by the pitman 'i to the ball 8 at the rear end of the cylindrical rod or lever 3 slidably mounted in the fulcrum guide-. sleeve Ill the central portion Ii of which is of cubical form and has projecting from its lateral 5 faces the alined pivot-studs l2 journaled in the slide-blocks l3 which work in the guideways It in the bed i. The slide-blocks i3 contact the side faces of the cubical central portion I i of the fulcrum-sleeve Ill and are heldon the pivot-pins 10 i2 by the cap-screws ill. v

At its forked forward end the lever 9 is connected by the pivot-pin ii to the lower end of the elbow-shaped arm ll rigid with the needlebar l8 which is mounted for vertical reciproca- 15 tion in the guideway IS in the bed I. The needlebar i8 carries the usual hook-needle 29 and eyepointed needle 2i arranged in side-by-side relation in the holder 22 fixed to the needle-bar. The lever 9 has fixed to it, adjacent its opposite ends, the guide-blocks 23 which work in vertical guideways between the guide-bars 24.

It will be understood that the length of the stroke imparted to the needle-bar i8 by the crank 6 will depend upon the position of the 25 fulcrum-studs l2 and their bearing blocks i3 in the guideways It. Further, it will be observed in Fig. 1, that when the crank 6 is at its highest point and the needle-bar i3 is at the lower limit of its stroke, the lever 9 is in parallelism with the guideways it which are inclined downwardly from their rearward ends toward the pivot I6. Hence adjustment of the fulcrum block il changes only the upper limit of the needle-stroke. This adjustment is made to suit the thickness of work to be sewn; the thicker the work, the longer is the required needle-stroke.

One of the guide-blocks i3, Figs. 1, 4 and 12, is connected by a stud-screw 25 and link 26 to an arm 21 extending upwardly from a collar 28 rotatably supported on the stud-pin 29 fixed in the bed I by the set-screw 30. Diametrically keyed at 3| to the collar 28 is the hub 32 of a hand-operated adjusting lever 33 carrying a spring-pressed locking-pin 34 receivable in any one of a series of locking apertures 35 in the plate 36 which is screwed to the machine frame.

It will be understood that the operator may, at a moment's notice, shift the needle-bar fulcrum block ii to any desired position and lock it in such position, by manipulation of the hand-lever 33. The fulcrum-block ii is thus positively locked in adjusted position against displacement by any reactionary forces to which it may be subjected under high speed operating conditions.

Cooperating with the needles 20, 2|, in the usual manner, are the loop-taking means or loopers 31, 38 which are carried by the slideframe 38 movable vertically in the head 4. The looper 31, which seizes a thread-loop from the eye-pointed needle 2| and moves in a plane at one side of and parallel to the plane of the needles, is mounted on the looper-lever 40 which is fulcrumed at 4| in the slide-frame 39. The looper 38, which carries one limb of the seized thread-loop into the barb of the hook-needle 20,

is mounted on the looper-carrier 42 which rocks on the pintles 43 and receives motion from the looper-lever 40 through the link-connection 44, all as disclosed in said United States Patent No.

2,034,706. The looper-mechanism is actuated by the usual crank-arm 45 on the rock-shaft 46 within the bracket-arm 3; the crank-arm 45 being pivotally connected at its lower end to a slide-block 41 embracing the looper-lever 40.

According to the present improvement, the looper-carrying slide-frame 39 is yieldingly connected to the manually adjustable means for varying and unyieldingly maintaining the length of stroke of the needle-bar. The connection preferably comprises a ball-stud 48 which is mounted on the slide-frame 33 and is connected by the link 49 to the crank-arm 50 on the rockshaft 5| journaled within and lengthwise of the bracket-arm 3. The rock-shaft 5| is formed at its rear end with an integral arm 52 having at its end a lateral extension 53 which extends over a lever 54 of adjustable length loosely fulcrumed on the rock-shaft 5|. A grass-hopper spring 55 coiled about a screw 55 in the rock-shaft 5| has one of its legs anchored in a hole in the arm 52. The other leg of the spring underlaps the arm 54. This spring is comparatively weak, as it is only required to be strong enough torestore the slide-frame 39 to its normal sewing position after having been displaced therefrom by the operator in raising the presser-foot for removal and insertion of work. The arm 54, which is of adjustable length, comprises two sections held together by the usual screw-and-slot expedient 51.

The arm 54 is connected at its free end to the upper end of the link 58 which at its lower end is connected to one arm 59 of a bell-crank lever fulcrumed on the fixed stud 60. The other arm 6| of the bell-crank lever is connected by the link 62 to the stud-screw 25 on the slide-block I 3 to which the manually adjustable lever 33 is connected.

It will be understood from the foregoing that when the manually operable lever 33 is shifted to and locked in a selected position of adjustment, the length of the needle-stroke will be determined by the position of the needle-lever fulcrum block I I which, through the described connections, also determines the operative or sewing elevation of the slide-frame 3! which carries the loopers.

Slidably mounted in the head 4, alongside the slide-frame 39, is the comparatively light weight presser-bar 63 carrying the usual presser-foot 64 with which the usual feed-dog 65 cooperates to feed the work 66. The presser-bar 63 has rigidly secured thereto an arm 51 having at its free end a roller 58 in position to be engaged by the usual manually operated presser-bar-lifting cam-lever 69. The arm 61 has an upstanding branch I0 which is apertured at H, Fig. 6, to receive the free end of a cantilever spring 12 anchored at its rear end 13 in the internal frame 75 lug I4 and carrying a guide-block 15, Fig. 1,

having a non-threaded hole receiving the lower end of the presser-bar-spring adjusting screw 16. The light-weight presser-bar has a limited working movement unaccompanied by movement of the heavier slide-frame 39 but has a shoulder I! which engages and lifts the slide-frame when the cam-lever 59 is operated to raise the presserbar for removal and insertion of work. The comparatively light spring 1'2 exerts only enough downward pressure upon the light-weight presserbar 63 to properly hold the work for the feeding action of the feed-dog 65 which works as usual through an aperture in the work-support 65'.

The manually operated adjusting lever 33 is preferably so set that during the sewing of work of a given thickness, the presser-bar shoulder TI does not engage and lift the slide-frame 39. The yielding connection (spring 55) between the slideframe 39 and the locked adjusting lever 33, permits the slide-frame to rise when the lifting lever 69 is manipulated for removal and insertion of work. The strong slide-frame springs of U. S. PatentsNos. 1,429,399 and 2,034,706, heretofore, used to resist displacement of the slide-frame under operative stresses set up in the running of the machine, are thus eliminated and the operator is not obliged to overcome the resistance of a strong spring in lifting the presser-bar.

The invention is not to be understood as limited to the details of construction and relative arrangements of parts shown and described, as the drawings and foregoing description are merely a disclosure of one embodiment of the invention. Various modifications may obviously be made by those skilled in the art within the scope and spirit of the invention.

Having thus set forth the nature of the invention, what I claim herein is:-

1. A sewing machine having a reciprocatory needle, means to reciprocate said needle including a manually adjustable needle-stroke-varying element and unyielding means to prevent displacement of said element from its adjusted position under operative stresses set up in running the machine, a loop-taker cooperating with said needle to form stitches, a loop-taker support, and positioning means for said loop-taker support yieldingly connected to said needle-stroke-varying element.

2. A sewing machine having reciprocatory hook and eye-pointed needles, manually operated means to select and unyieldingly maintain a desired length of stroke of said needles to suit the thickness of work to be stitched, a movable loopersupport yieldingly connected to said means, one

or more loopers carried by said looper-support,

and means to move said looper-support for removal and insertion of work.

3. A sewing machine having reciprocatory hook and eye-pointed needles, manually operated means to adjust and unyieldingly maintain the length of needle-stroke to suit the thickness of work to be stitched, looper means cooperating with said needles to form stitches, a movable support for said looper means, a yielding connection between said looper support and said needle-stroke adjusting means, to position said looper support for cooperation of said looper means with said needles, a feed-dog, a presserfoot, a spring-pressed presser-bar movable independently of said looper support, and manually operated means to lift said presser-bar and looper support for removal and insertion of work.

4. A sewing machine having, in combination, a work-support, reciprocatory hookand eye-' pointed needles mounted below the work-support, manually operated means to adjust the length of stroke of said needles, loop-taking means cooperating with said needles above the work-support, a slide-frame carrying said loop-taking means, a feed-dog, a presser-foot, a spring-pressed presserbar carrying said presser-foot, means on said presser-bar to lift said slide-frame when the presser-bar is raised for removal and insertion of work, and a yielding slide-frame-positioning connection between said slide-frame and the needlestroke adjusting means.

5. A sewing machine having a reciprocatory needle, a needle-operating lever, a shiftable fulcrum for said lever, manually operated means to adjust the position of said fulcrum and lock it in adjusted position, a looper-support yieldingly connected to said fulcrum adjusting means, and a looper carried by said looper support.

6. A straw-braid-sewing machine having a frame formed with a bed and an overhanging bracket-arm, a work-support on said bed, reciprocatory hook and eye-pointed needles mounted in said bed, means in said bed to reciprocate said needles, a manually adjustable lever on said bed and connections therewith for varying the upper limit of the needle-stroke, a vertically movable looper-support mounted in said bracketarm, loopers carried by said looper-support, yielding means interconnecting said needle-strokevarying means with said looper-support to yieldingly position said looper-support for cooperation of said loopers with said needles, a feeddog, a spring-pressed presser-foot movable vertically independently of the looper-support while the machine is sewing, and means to lift said presser-foot and looper-support for removal and insertion of work.

7. A straw-braid-sewing machine having a frame including a bed and a bracket-arm, reciprocatory hook and eye-pointed needles mounted in said bed, a movable looper support mounted in said bracket-arm, loopers carried by said loopersupport, a manually operated lever on said bed and connections to simultaneously adjust the length of stroke of said needles and the working elevation of said loopers, and means to lock said lever in adjusted position.

RUDOLPH BECKER. 

